package com.lss.study.algorithm.niuke.T10;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * 功能描述：
 *
 * @Date: 2022/2/19 18:21
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextLine()) {
            String str = sc.nextLine();
            Set<Character> set = new HashSet<>();
            for (char c : str.toCharArray()) {
                set.add(c);
            }
            System.out.println(set.size());
        }
    }
}
